MPX2784_synpic46359: Diagram of head impact. The brain may move within the skull, causing torque (twisting) of the brainstem that may lead to symptoms - including loss of consciousness. Dysfunction may result from disruption of the ascending reticular activating system (ARAS) in the posterior brainstem. The disruption may be transient from an electrical discharge, transient ischemia, or from a brainstem hemorrhage - that might produce long-term/chronic dysfunction. The relatively large volume and mass of the human cerebral hemispheres - supported by the much smaller brainstem - makes this injury (LOC) more difficult to model in animals.

MPX2784_synpic46359: Diagram of head impact. The brain may move within the skull, causing torque (twisting) of the brainstem that may lead to symptoms - including loss of consciousness. Dysfunction may result from disruption of the ascending reticular activating system (ARAS) in the posterior brainstem. The disruption may be transient from an electrical discharge, transient ischemia, or from a brainstem hemorrhage - that might produce long-term/chronic dysfunction. The relatively large volume and mass of the human cerebral hemispheres - supported by the much smaller brainstem - makes this injury (LOC) more difficult to model in animals.